A new reinforced winding of Bi-2212 coils for 30 T class superconducting magnets

We proposed a new reinforcing technique against a huge electromagnetic hoop stress for HTS pancake coils in a high magnetic field with improving their strain tolerance. Two react and wind type Bi-2212 test pancake coils were prepared; one was a standard coil and another was a compressively pre-strai ned coil. Their mechanical and transport current properties were investigat ed in liquid Helium (T = 4.2 K) and a magnetic field of 10 T. The mechanica l properties of the two were almost the same, however, the pre-strained coi l could transport current without any degradation up to a strain of 0.3% th ough a significant degradation occurred at >0.18% for the standard coil. (C ) 2001 Elsevier Science B.V. All rights reserved.